Heat generation of vapor spray is known. Illustrative of this type of prior art are U.S. Pat. No. 2,128,263 to Ofeldt and U.S. Pat. No. 2,790,063 to Bok et al. The Ofeldt patent shows an apparatus for generating a spray in which the fluid to be sprayed is passed through a heating coil 4. Heat is provided to the heating coil using a fire pot. The vapor sprayer of Bok includes an easily transportable reservoir having electrical heating means provided within the reservoir. The electrical heating means is immersed directly into the fluid to be vaporized.
This prior art and the other prior art of which we are aware fails to provide an apparatus and process for generating a vapor spray from a volatile fluid that heats the volatile fluid within a heat exchanger in which the fluid is exterior to a heating element, that is capable of producing a continuous vapor spray, that modulates flow of the fluid prior to entry thereof into the heat exchanger whereby a selected pressure is maintained downstream from a pump drawing the fluid from a reservoir, and that controls the velocity of the stream of fluid as it enters the heat exchanger so as to ensure that the fluid is at a selected temperature when discharged from the heat exchanger.